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nd6.c
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nd6.c
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/* $NetBSD: nd6.c,v 1.99.4.2 2006/05/24 15:50:45 tron Exp $ */
/* $KAME: nd6.c,v 1.279 2002/06/08 11:16:51 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.99.4.2 2006/05/24 15:50:45 tron Exp $");
#include "opt_ipsec.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/protosw.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/syslog.h>
#include <sys/queue.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/if_ether.h>
#include <net/if_fddi.h>
#include <net/if_arc.h>
#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#include <netinet6/nd6.h>
#include <netinet/icmp6.h>
#ifdef IPSEC
#include <netinet6/ipsec.h>
#endif
#include <net/net_osdep.h>
#define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
#define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
#define SIN6(s) ((struct sockaddr_in6 *)s)
#define SDL(s) ((struct sockaddr_dl *)s)
/* timer values */
int nd6_prune = 1; /* walk list every 1 seconds */
int nd6_delay = 5; /* delay first probe time 5 second */
int nd6_umaxtries = 3; /* maximum unicast query */
int nd6_mmaxtries = 3; /* maximum multicast query */
int nd6_useloopback = 1; /* use loopback interface for local traffic */
int nd6_gctimer = (60 * 60 * 24); /* 1 day: garbage collection timer */
/* preventing too many loops in ND option parsing */
int nd6_maxndopt = 10; /* max # of ND options allowed */
int nd6_maxnudhint = 0; /* max # of subsequent upper layer hints */
int nd6_maxqueuelen = 1; /* max # of packets cached in unresolved ND entries */
#ifdef ND6_DEBUG
int nd6_debug = 1;
#else
int nd6_debug = 0;
#endif
/* for debugging? */
static int nd6_inuse, nd6_allocated;
struct llinfo_nd6 llinfo_nd6 = {&llinfo_nd6, &llinfo_nd6};
struct nd_drhead nd_defrouter;
struct nd_prhead nd_prefix = { 0 };
int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
static struct sockaddr_in6 all1_sa;
static void nd6_setmtu0 __P((struct ifnet *, struct nd_ifinfo *));
static void nd6_slowtimo __P((void *));
static int regen_tmpaddr __P((struct in6_ifaddr *));
static struct llinfo_nd6 *nd6_free __P((struct rtentry *, int));
static void nd6_llinfo_timer __P((void *));
static void clear_llinfo_pqueue __P((struct llinfo_nd6 *));
struct callout nd6_slowtimo_ch = CALLOUT_INITIALIZER;
struct callout nd6_timer_ch = CALLOUT_INITIALIZER;
extern struct callout in6_tmpaddrtimer_ch;
static int fill_drlist __P((void *, size_t *, size_t));
static int fill_prlist __P((void *, size_t *, size_t));
MALLOC_DEFINE(M_IP6NDP, "NDP", "IPv6 Neighbour Discovery");
void
nd6_init()
{
static int nd6_init_done = 0;
int i;
if (nd6_init_done) {
log(LOG_NOTICE, "nd6_init called more than once(ignored)\n");
return;
}
all1_sa.sin6_family = AF_INET6;
all1_sa.sin6_len = sizeof(struct sockaddr_in6);
for (i = 0; i < sizeof(all1_sa.sin6_addr); i++)
all1_sa.sin6_addr.s6_addr[i] = 0xff;
/* initialization of the default router list */
TAILQ_INIT(&nd_defrouter);
nd6_init_done = 1;
/* start timer */
callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
nd6_slowtimo, NULL);
}
struct nd_ifinfo *
nd6_ifattach(ifp)
struct ifnet *ifp;
{
struct nd_ifinfo *nd;
nd = (struct nd_ifinfo *)malloc(sizeof(*nd), M_IP6NDP, M_WAITOK);
bzero(nd, sizeof(*nd));
nd->initialized = 1;
nd->chlim = IPV6_DEFHLIM;
nd->basereachable = REACHABLE_TIME;
nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
nd->retrans = RETRANS_TIMER;
/*
* Note that the default value of ip6_accept_rtadv is 0, which means
* we won't accept RAs by default even if we set ND6_IFF_ACCEPT_RTADV
* here.
*/
nd->flags = (ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV);
/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
nd6_setmtu0(ifp, nd);
return nd;
}
void
nd6_ifdetach(nd)
struct nd_ifinfo *nd;
{
free(nd, M_IP6NDP);
}
void
nd6_setmtu(ifp)
struct ifnet *ifp;
{
nd6_setmtu0(ifp, ND_IFINFO(ifp));
}
void
nd6_setmtu0(ifp, ndi)
struct ifnet *ifp;
struct nd_ifinfo *ndi;
{
u_int32_t omaxmtu;
omaxmtu = ndi->maxmtu;
switch (ifp->if_type) {
case IFT_ARCNET:
ndi->maxmtu = MIN(ARC_PHDS_MAXMTU, ifp->if_mtu); /* RFC2497 */
break;
case IFT_FDDI:
ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu);
break;
default:
ndi->maxmtu = ifp->if_mtu;
break;
}
/*
* Decreasing the interface MTU under IPV6 minimum MTU may cause
* undesirable situation. We thus notify the operator of the change
* explicitly. The check for omaxmtu is necessary to restrict the
* log to the case of changing the MTU, not initializing it.
*/
if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
log(LOG_NOTICE, "nd6_setmtu0: new link MTU on %s (%lu) is too"
" small for IPv6 which needs %lu\n",
if_name(ifp), (unsigned long)ndi->maxmtu, (unsigned long)
IPV6_MMTU);
}
if (ndi->maxmtu > in6_maxmtu)
in6_setmaxmtu(); /* check all interfaces just in case */
}
void
nd6_option_init(opt, icmp6len, ndopts)
void *opt;
int icmp6len;
union nd_opts *ndopts;
{
bzero(ndopts, sizeof(*ndopts));
ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
ndopts->nd_opts_last
= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
if (icmp6len == 0) {
ndopts->nd_opts_done = 1;
ndopts->nd_opts_search = NULL;
}
}
/*
* Take one ND option.
*/
struct nd_opt_hdr *
nd6_option(ndopts)
union nd_opts *ndopts;
{
struct nd_opt_hdr *nd_opt;
int olen;
if (ndopts == NULL)
panic("ndopts == NULL in nd6_option");
if (ndopts->nd_opts_last == NULL)
panic("uninitialized ndopts in nd6_option");
if (ndopts->nd_opts_search == NULL)
return NULL;
if (ndopts->nd_opts_done)
return NULL;
nd_opt = ndopts->nd_opts_search;
/* make sure nd_opt_len is inside the buffer */
if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
bzero(ndopts, sizeof(*ndopts));
return NULL;
}
olen = nd_opt->nd_opt_len << 3;
if (olen == 0) {
/*
* Message validation requires that all included
* options have a length that is greater than zero.
*/
bzero(ndopts, sizeof(*ndopts));
return NULL;
}
ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
/* option overruns the end of buffer, invalid */
bzero(ndopts, sizeof(*ndopts));
return NULL;
} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
/* reached the end of options chain */
ndopts->nd_opts_done = 1;
ndopts->nd_opts_search = NULL;
}
return nd_opt;
}
/*
* Parse multiple ND options.
* This function is much easier to use, for ND routines that do not need
* multiple options of the same type.
*/
int
nd6_options(ndopts)
union nd_opts *ndopts;
{
struct nd_opt_hdr *nd_opt;
int i = 0;
if (ndopts == NULL)
panic("ndopts == NULL in nd6_options");
if (ndopts->nd_opts_last == NULL)
panic("uninitialized ndopts in nd6_options");
if (ndopts->nd_opts_search == NULL)
return 0;
while (1) {
nd_opt = nd6_option(ndopts);
if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
/*
* Message validation requires that all included
* options have a length that is greater than zero.
*/
icmp6stat.icp6s_nd_badopt++;
bzero(ndopts, sizeof(*ndopts));
return -1;
}
if (nd_opt == NULL)
goto skip1;
switch (nd_opt->nd_opt_type) {
case ND_OPT_SOURCE_LINKADDR:
case ND_OPT_TARGET_LINKADDR:
case ND_OPT_MTU:
case ND_OPT_REDIRECTED_HEADER:
if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
nd6log((LOG_INFO,
"duplicated ND6 option found (type=%d)\n",
nd_opt->nd_opt_type));
/* XXX bark? */
} else {
ndopts->nd_opt_array[nd_opt->nd_opt_type]
= nd_opt;
}
break;
case ND_OPT_PREFIX_INFORMATION:
if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
ndopts->nd_opt_array[nd_opt->nd_opt_type]
= nd_opt;
}
ndopts->nd_opts_pi_end =
(struct nd_opt_prefix_info *)nd_opt;
break;
default:
/*
* Unknown options must be silently ignored,
* to accomodate future extension to the protocol.
*/
nd6log((LOG_DEBUG,
"nd6_options: unsupported option %d - "
"option ignored\n", nd_opt->nd_opt_type));
}
skip1:
i++;
if (i > nd6_maxndopt) {
icmp6stat.icp6s_nd_toomanyopt++;
nd6log((LOG_INFO, "too many loop in nd opt\n"));
break;
}
if (ndopts->nd_opts_done)
break;
}
return 0;
}
/*
* ND6 timer routine to handle ND6 entries
*/
void
nd6_llinfo_settimer(ln, xtick)
struct llinfo_nd6 *ln;
long xtick;
{
int s;
s = splsoftnet();
if (xtick < 0) {
ln->ln_expire = 0;
ln->ln_ntick = 0;
callout_stop(&ln->ln_timer_ch);
} else {
ln->ln_expire = time.tv_sec + xtick / hz;
if (xtick > INT_MAX) {
ln->ln_ntick = xtick - INT_MAX;
callout_reset(&ln->ln_timer_ch, INT_MAX,
nd6_llinfo_timer, ln);
} else {
ln->ln_ntick = 0;
callout_reset(&ln->ln_timer_ch, xtick,
nd6_llinfo_timer, ln);
}
}
splx(s);
}
static void
nd6_llinfo_timer(arg)
void *arg;
{
int s;
struct llinfo_nd6 *ln;
struct rtentry *rt;
const struct sockaddr_in6 *dst;
struct ifnet *ifp;
struct nd_ifinfo *ndi = NULL;
s = splsoftnet();
ln = (struct llinfo_nd6 *)arg;
if (ln->ln_ntick > 0) {
nd6_llinfo_settimer(ln, ln->ln_ntick);
splx(s);
return;
}
if ((rt = ln->ln_rt) == NULL)
panic("ln->ln_rt == NULL");
if ((ifp = rt->rt_ifp) == NULL)
panic("ln->ln_rt->rt_ifp == NULL");
ndi = ND_IFINFO(ifp);
dst = (struct sockaddr_in6 *)rt_key(rt);
/* sanity check */
if (rt->rt_llinfo && (struct llinfo_nd6 *)rt->rt_llinfo != ln)
panic("rt_llinfo(%p) is not equal to ln(%p)",
rt->rt_llinfo, ln);
if (!dst)
panic("dst=0 in nd6_timer(ln=%p)", ln);
switch (ln->ln_state) {
case ND6_LLINFO_INCOMPLETE:
if (ln->ln_asked < nd6_mmaxtries) {
ln->ln_asked++;
nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000);
nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
} else {
struct mbuf *m = ln->ln_hold;
if (m) {
struct mbuf *m0;
/*
* assuming every packet in ln_hold has
* the same IP header
*/
m0 = m->m_nextpkt;
m->m_nextpkt = NULL;
icmp6_error2(m, ICMP6_DST_UNREACH,
ICMP6_DST_UNREACH_ADDR, 0, rt->rt_ifp);
ln->ln_hold = m0;
clear_llinfo_pqueue(ln);
}
(void)nd6_free(rt, 0);
ln = NULL;
}
break;
case ND6_LLINFO_REACHABLE:
if (!ND6_LLINFO_PERMANENT(ln)) {
ln->ln_state = ND6_LLINFO_STALE;
nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
}
break;
case ND6_LLINFO_STALE:
/* Garbage Collection(RFC 2461 5.3) */
if (!ND6_LLINFO_PERMANENT(ln)) {
(void)nd6_free(rt, 1);
ln = NULL;
}
break;
case ND6_LLINFO_DELAY:
if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
/* We need NUD */
ln->ln_asked = 1;
ln->ln_state = ND6_LLINFO_PROBE;
nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000);
nd6_ns_output(ifp, &dst->sin6_addr,
&dst->sin6_addr, ln, 0);
} else {
ln->ln_state = ND6_LLINFO_STALE; /* XXX */
nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
}
break;
case ND6_LLINFO_PROBE:
if (ln->ln_asked < nd6_umaxtries) {
ln->ln_asked++;
nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000);
nd6_ns_output(ifp, &dst->sin6_addr,
&dst->sin6_addr, ln, 0);
} else {
(void)nd6_free(rt, 0);
ln = NULL;
}
break;
}
splx(s);
}
/*
* ND6 timer routine to expire default route list and prefix list
*/
void
nd6_timer(ignored_arg)
void *ignored_arg;
{
int s;
struct nd_defrouter *dr;
struct nd_prefix *pr;
struct in6_ifaddr *ia6, *nia6;
struct in6_addrlifetime *lt6;
s = splsoftnet();
callout_reset(&nd6_timer_ch, nd6_prune * hz,
nd6_timer, NULL);
/* expire default router list */
dr = TAILQ_FIRST(&nd_defrouter);
while (dr) {
if (dr->expire && dr->expire < time.tv_sec) {
struct nd_defrouter *t;
t = TAILQ_NEXT(dr, dr_entry);
defrtrlist_del(dr);
dr = t;
} else {
dr = TAILQ_NEXT(dr, dr_entry);
}
}
/*
* expire interface addresses.
* in the past the loop was inside prefix expiry processing.
* However, from a stricter speci-confrmance standpoint, we should
* rather separate address lifetimes and prefix lifetimes.
*/
addrloop:
for (ia6 = in6_ifaddr; ia6; ia6 = nia6) {
nia6 = ia6->ia_next;
/* check address lifetime */
lt6 = &ia6->ia6_lifetime;
if (IFA6_IS_INVALID(ia6)) {
int regen = 0;
/*
* If the expiring address is temporary, try
* regenerating a new one. This would be useful when
* we suspended a laptop PC, then turned it on after a
* period that could invalidate all temporary
* addresses. Although we may have to restart the
* loop (see below), it must be after purging the
* address. Otherwise, we'd see an infinite loop of
* regeneration.
*/
if (ip6_use_tempaddr &&
(ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
if (regen_tmpaddr(ia6) == 0)
regen = 1;
}
in6_purgeaddr(&ia6->ia_ifa);
if (regen)
goto addrloop; /* XXX: see below */
} else if (IFA6_IS_DEPRECATED(ia6)) {
int oldflags = ia6->ia6_flags;
ia6->ia6_flags |= IN6_IFF_DEPRECATED;
/*
* If a temporary address has just become deprecated,
* regenerate a new one if possible.
*/
if (ip6_use_tempaddr &&
(ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
(oldflags & IN6_IFF_DEPRECATED) == 0) {
if (regen_tmpaddr(ia6) == 0) {
/*
* A new temporary address is
* generated.
* XXX: this means the address chain
* has changed while we are still in
* the loop. Although the change
* would not cause disaster (because
* it's not a deletion, but an
* addition,) we'd rather restart the
* loop just for safety. Or does this
* significantly reduce performance??
*/
goto addrloop;
}
}
} else {
/*
* A new RA might have made a deprecated address
* preferred.
*/
ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
}
}
/* expire prefix list */
pr = nd_prefix.lh_first;
while (pr) {
/*
* check prefix lifetime.
* since pltime is just for autoconf, pltime processing for
* prefix is not necessary.
*/
if (pr->ndpr_vltime != ND6_INFINITE_LIFETIME &&
time.tv_sec - pr->ndpr_lastupdate > pr->ndpr_vltime) {
struct nd_prefix *t;
t = pr->ndpr_next;
/*
* address expiration and prefix expiration are
* separate. NEVER perform in6_purgeaddr here.
*/
prelist_remove(pr);
pr = t;
} else
pr = pr->ndpr_next;
}
splx(s);
}
static int
regen_tmpaddr(ia6)
struct in6_ifaddr *ia6; /* deprecated/invalidated temporary address */
{
struct ifaddr *ifa;
struct ifnet *ifp;
struct in6_ifaddr *public_ifa6 = NULL;
ifp = ia6->ia_ifa.ifa_ifp;
for (ifa = ifp->if_addrlist.tqh_first; ifa;
ifa = ifa->ifa_list.tqe_next) {
struct in6_ifaddr *it6;
if (ifa->ifa_addr->sa_family != AF_INET6)
continue;
it6 = (struct in6_ifaddr *)ifa;
/* ignore no autoconf addresses. */
if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
continue;
/* ignore autoconf addresses with different prefixes. */
if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
continue;
/*
* Now we are looking at an autoconf address with the same
* prefix as ours. If the address is temporary and is still
* preferred, do not create another one. It would be rare, but
* could happen, for example, when we resume a laptop PC after
* a long period.
*/
if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
!IFA6_IS_DEPRECATED(it6)) {
public_ifa6 = NULL;
break;
}
/*
* This is a public autoconf address that has the same prefix
* as ours. If it is preferred, keep it. We can't break the
* loop here, because there may be a still-preferred temporary
* address with the prefix.
*/
if (!IFA6_IS_DEPRECATED(it6))
public_ifa6 = it6;
}
if (public_ifa6 != NULL) {
int e;
/*
* Random factor is introduced in the preferred lifetime, so
* we do not need additional delay (3rd arg to in6_tmpifadd).
*/
if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
" tmp addr, errno=%d\n", e);
return (-1);
}
return (0);
}
return (-1);
}
/*
* Nuke neighbor cache/prefix/default router management table, right before
* ifp goes away.
*/
void
nd6_purge(ifp)
struct ifnet *ifp;
{
struct llinfo_nd6 *ln, *nln;
struct nd_defrouter *dr, *ndr;
struct nd_prefix *pr, *npr;
/*
* Nuke default router list entries toward ifp.
* We defer removal of default router list entries that is installed
* in the routing table, in order to keep additional side effects as
* small as possible.
*/
for (dr = TAILQ_FIRST(&nd_defrouter); dr; dr = ndr) {
ndr = TAILQ_NEXT(dr, dr_entry);
if (dr->installed)
continue;
if (dr->ifp == ifp)
defrtrlist_del(dr);
}
for (dr = TAILQ_FIRST(&nd_defrouter); dr; dr = ndr) {
ndr = TAILQ_NEXT(dr, dr_entry);
if (!dr->installed)
continue;
if (dr->ifp == ifp)
defrtrlist_del(dr);
}
/* Nuke prefix list entries toward ifp */
for (pr = nd_prefix.lh_first; pr; pr = npr) {
npr = pr->ndpr_next;
if (pr->ndpr_ifp == ifp) {
/*
* Because if_detach() does *not* release prefixes
* while purging addresses the reference count will
* still be above zero. We therefore reset it to
* make sure that the prefix really gets purged.
*/
pr->ndpr_refcnt = 0;
/*
* Previously, pr->ndpr_addr is removed as well,
* but I strongly believe we don't have to do it.
* nd6_purge() is only called from in6_ifdetach(),
* which removes all the associated interface addresses
* by itself.
* (jinmei@kame.net 20010129)
*/
prelist_remove(pr);
}
}
/* cancel default outgoing interface setting */
if (nd6_defifindex == ifp->if_index)
nd6_setdefaultiface(0);
if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
/* refresh default router list */
defrouter_select();
}
/*
* Nuke neighbor cache entries for the ifp.
* Note that rt->rt_ifp may not be the same as ifp,
* due to KAME goto ours hack. See RTM_RESOLVE case in
* nd6_rtrequest(), and ip6_input().
*/
ln = llinfo_nd6.ln_next;
while (ln && ln != &llinfo_nd6) {
struct rtentry *rt;
struct sockaddr_dl *sdl;
nln = ln->ln_next;
rt = ln->ln_rt;
if (rt && rt->rt_gateway &&
rt->rt_gateway->sa_family == AF_LINK) {
sdl = (struct sockaddr_dl *)rt->rt_gateway;
if (sdl->sdl_index == ifp->if_index)
nln = nd6_free(rt, 0);
}
ln = nln;
}
}
struct rtentry *
nd6_lookup(addr6, create, ifp)
struct in6_addr *addr6;
int create;
struct ifnet *ifp;
{
struct rtentry *rt;
struct sockaddr_in6 sin6;
bzero(&sin6, sizeof(sin6));
sin6.sin6_len = sizeof(struct sockaddr_in6);
sin6.sin6_family = AF_INET6;
sin6.sin6_addr = *addr6;
rt = rtalloc1((struct sockaddr *)&sin6, create);
if (rt && (rt->rt_flags & RTF_LLINFO) == 0) {
/*
* This is the case for the default route.
* If we want to create a neighbor cache for the address, we
* should free the route for the destination and allocate an
* interface route.
*/
if (create) {
RTFREE(rt);
rt = NULL;
}
}
if (rt == NULL) {
if (create && ifp) {
int e;
/*
* If no route is available and create is set,
* we allocate a host route for the destination
* and treat it like an interface route.
* This hack is necessary for a neighbor which can't
* be covered by our own prefix.
*/
struct ifaddr *ifa =
ifaof_ifpforaddr((struct sockaddr *)&sin6, ifp);
if (ifa == NULL)
return (NULL);
/*
* Create a new route. RTF_LLINFO is necessary
* to create a Neighbor Cache entry for the
* destination in nd6_rtrequest which will be
* called in rtrequest via ifa->ifa_rtrequest.
*/
if ((e = rtrequest(RTM_ADD, (struct sockaddr *)&sin6,
ifa->ifa_addr, (struct sockaddr *)&all1_sa,
(ifa->ifa_flags | RTF_HOST | RTF_LLINFO) &
~RTF_CLONING, &rt)) != 0) {
#if 0
log(LOG_ERR,
"nd6_lookup: failed to add route for a "
"neighbor(%s), errno=%d\n",
ip6_sprintf(addr6), e);
#endif
return (NULL);
}
if (rt == NULL)
return (NULL);
if (rt->rt_llinfo) {
struct llinfo_nd6 *ln =
(struct llinfo_nd6 *)rt->rt_llinfo;
ln->ln_state = ND6_LLINFO_NOSTATE;
}
} else
return (NULL);
}
rt->rt_refcnt--;
/*
* Validation for the entry.
* Note that the check for rt_llinfo is necessary because a cloned
* route from a parent route that has the L flag (e.g. the default
* route to a p2p interface) may have the flag, too, while the
* destination is not actually a neighbor.
* XXX: we can't use rt->rt_ifp to check for the interface, since
* it might be the loopback interface if the entry is for our
* own address on a non-loopback interface. Instead, we should
* use rt->rt_ifa->ifa_ifp, which would specify the REAL
* interface.
* Note also that ifa_ifp and ifp may differ when we connect two
* interfaces to a same link, install a link prefix to an interface,
* and try to install a neighbor cache on an interface that does not
* have a route to the prefix.
*/
if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL ||
(ifp && rt->rt_ifa->ifa_ifp != ifp)) {
if (create) {
nd6log((LOG_DEBUG,
"nd6_lookup: failed to lookup %s (if = %s)\n",
ip6_sprintf(addr6),
ifp ? if_name(ifp) : "unspec"));
}
return (NULL);
}
return (rt);
}
/*
* Detect if a given IPv6 address identifies a neighbor on a given link.
* XXX: should take care of the destination of a p2p link?
*/
int
nd6_is_addr_neighbor(addr, ifp)
struct sockaddr_in6 *addr;
struct ifnet *ifp;
{
struct nd_prefix *pr;
/*
* A link-local address is always a neighbor.
* XXX: a link does not necessarily specify a single interface.
*/
if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
struct sockaddr_in6 sin6_copy;
u_int32_t zone;
/*
* We need sin6_copy since sa6_recoverscope() may modify the
* content (XXX).
*/
sin6_copy = *addr;
if (sa6_recoverscope(&sin6_copy))
return (0); /* XXX: should be impossible */
if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
return (0);
if (sin6_copy.sin6_scope_id == zone)
return (1);
else
return (0);
}
/*
* If the address matches one of our on-link prefixes, it should be a
* neighbor.
*/
for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
if (pr->ndpr_ifp != ifp)
continue;
if (!(pr->ndpr_stateflags & NDPRF_ONLINK))
continue;
if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
&addr->sin6_addr, &pr->ndpr_mask))
return (1);
}
/*
* If the default router list is empty, all addresses are regarded
* as on-link, and thus, as a neighbor.
* XXX: we restrict the condition to hosts, because routers usually do
* not have the "default router list".
*/
if (!ip6_forwarding && TAILQ_FIRST(&nd_defrouter) == NULL &&
nd6_defifindex == ifp->if_index) {
return (1);
}
/*
* Even if the address matches none of our addresses, it might be
* in the neighbor cache.
*/
if (nd6_lookup(&addr->sin6_addr, 0, ifp) != NULL)
return (1);
return (0);
}
/*
* Free an nd6 llinfo entry.
* Since the function would cause significant changes in the kernel, DO NOT
* make it global, unless you have a strong reason for the change, and are sure
* that the change is safe.
*/
static struct llinfo_nd6 *
nd6_free(rt, gc)
struct rtentry *rt;
int gc;
{
struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo, *next;
struct in6_addr in6 = ((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
struct nd_defrouter *dr;
/*
* we used to have pfctlinput(PRC_HOSTDEAD) here.
* even though it is not harmful, it was not really necessary.
*/
/* cancel timer */